Dunkman Posted February 17, 2012 Share Posted February 17, 2012 Hard to bet against the NAM this close and it being so consistent! ] My sarcasm meter may be broken...you're joking right? Link to comment Share on other sites More sharing options...
HKY_WX Posted February 17, 2012 Share Posted February 17, 2012 ECens. This is actually a very nice cold air damming setup. There is quite a bit of cold air showing up now over the great lakes from the departing s/w. If you look at the 500mb pattern at 48/60 hours, it would argue for an even stronger HP situation. This will be an interesting weekend. Link to comment Share on other sites More sharing options...
RaleighWx Posted February 17, 2012 Share Posted February 17, 2012 A comparison of the locations at 12z Sunday of the 18z NAM, 12z ECMWF, 12z GFS, 12z UKMET, and 12z GGEM. One think to keep in mind the NAM uses the GFS for boundary conditions so in some ways those two are on the same team and so we have the ECMWF vs the Met Office vs NCEP vs CMC. Essentially 4 different centers with their own unique modeling capabailities. Notice the ECMWF and GGEm are almost in the same location, the NAm is furthest North, the GFS and UKMET are in similar locations. The UKMEt looks to take a further south track than the GFS though if the 48-60 time frame though I havent seen the 54 hour map. UKMET GGEM GFS NAM ECMWF Link to comment Share on other sites More sharing options...
BIG FROSTY Posted February 17, 2012 Share Posted February 17, 2012 My sarcasm meter may be broken...you're joking right? No model is perfect, but it is a short range model. If it's so funny why is everybody so interested in what has to say? Just saying!!! You can't just discard it!!! It may be correct it may not be? You tell me which model is right??? Link to comment Share on other sites More sharing options...
Tullioz Posted February 17, 2012 Share Posted February 17, 2012 A small portion of the latest discussion as of 3:40pm from Blacksburg for those along the NC/VA border: BY AFTERNOON WHEN COLDER AIR ARRIVES AND THINK BEST CHANCES FOR THE BANDING TO MOVE IN...BUT BY LATE DAY AND EARLY EVENING THE LOW WILL BE PULLING OUT AND DEFORMATION BAND WILL BE STARTING TO WEAKEN. THUS FINAL SNOW ACCUMS ARE NOT AS HIGH AS THE MODELS DIRECT OUTPUT SINCE THEY ARE NOT TAKING INTO ACCOUNT MELTING FROM THE SURFACE...WHICH WILL BE APPRECIABLE UNTIL VERY LATE SUNDAY AND INTO THE EVENING WHEN IT GETS DARK. This is exactly what I am expecting as far as the extent of accumulation into North Carolina at this point, as well as my reasoning for believing this to be the case. The storm will be pulling away once it gets cold enough, and temperatures at the surface are just too warm. Link to comment Share on other sites More sharing options...
tarheelwx Posted February 17, 2012 Share Posted February 17, 2012 Time to start seeing some maps. Interesting that NWS doens't even have Roanoke under a watch. TW Link to comment Share on other sites More sharing options...
Dunkman Posted February 17, 2012 Share Posted February 17, 2012 No model is perfect, but it is a short range model. If it's so funny why is everybody so interested in what has to say? Just saying!!! You can't just discard it!!! It may be correct it may not be? You tell me which model is right??? Raleighwx just posted some great maps...basically the NAM is substantially farther north than every other model that's worth looking at. That's not a limb I'd want to go out on. Link to comment Share on other sites More sharing options...
SBUWX23 Posted February 17, 2012 Share Posted February 17, 2012 The quality of the discussion here is no comparison to the NYC thread. Yes this storm is missing us in NYC, but there is so much better meteorology discussion here. Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 17, 2012 Share Posted February 17, 2012 NWS Blacksburg and Raleigh are finally putting some snow in the grids for areas outside of the mountains...roughly from a line around North Wilkesboro down east to Raleigh. NWS Greenville....not so much yet. Link to comment Share on other sites More sharing options...
GaWx Posted February 17, 2012 Share Posted February 17, 2012 Alan, I find it interesting that the progged track is a good bit further north than the avg. track of lows that have produced major snow at RDU and HKY as per your website. Do you think this is a concern as regards the chances of a major accumulation at those cities such as the ~5" shown by my vendor's 12z Euro map? Of course, I realize that the climo track is merely an avg. of all major storm tracks and that there is variability. Link to comment Share on other sites More sharing options...
packfan98 Posted February 17, 2012 Share Posted February 17, 2012 I saw snow probability maps from the SREF in the MA forum, but I'm not sure what site it came from. If anyone knows please post the panels that show the SE for us. SREFs look similar but are south a little, a little less bullish for the 8+probs as well. But look good for 3-6" for south VA and even northern NC. I wish there was a way to scroll south on the map...the fact that you can't shows that this far south shouldn't be getting snow. JK Link to comment Share on other sites More sharing options...
RaleighWx Posted February 17, 2012 Share Posted February 17, 2012 The Euro Ensemble mean is very similar looking to the op ECMWF w.r.t snowfall accumulation. It shows a band of 4-8 inches along the NC/VA border with the band extendeding probably 50-100 miles on either side and a 2-4 inch band surrounding that. RDU is probably near right on the 4inch line which runs roughly right along hte I-40 corridor. Link to comment Share on other sites More sharing options...
packbacker Posted February 17, 2012 Share Posted February 17, 2012 I saw snow probability maps from the SREF in the MA forum, but I'm not sure what site it came from. If anyone knows please post the panels that show the SE for us. You can play around with the maps here.... http://www.meteo.psu.edu/~gadomski/ewallsref.html Link to comment Share on other sites More sharing options...
packbacker Posted February 17, 2012 Share Posted February 17, 2012 Interesting SREF has shifted pretty good south... 09z SREF 15z SREF Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 17, 2012 Share Posted February 17, 2012 Link to comment Share on other sites More sharing options...
RaleighWx Posted February 17, 2012 Share Posted February 17, 2012 Alan, I find it interesting that the progged track is a good bit further north than the avg. track of lows that have produced major snow at RDU and HKY as per your website. Do you think this is a concern as regards the chances of a major accumulation at those cities such as the ~5" shown by my vendor's 12z Euro map? Of course, I realize that the climo track is merely an avg. of all major storm tracks and that there is variability. You would always like to see the track match the climo as that adds to confidence but the climo track is an average of all tracks so their are outliers on either side. The Jan 19th 1955 storm took a somewhat similar track that the Euro showss, but it was in mid-january with a colder/stronger high to the north. As did the Feb 9th 1967 storm. Just to name a couple. But yeah i would love to see a climo favored track but it doesnt always happen obviousluy. Link to comment Share on other sites More sharing options...
WeatherNC Posted February 17, 2012 Share Posted February 17, 2012 A comparison of the locations at 12z Sunday of the 18z NAM, 12z ECMWF, 12z GFS, 12z UKMET, and 12z GGEM. One think to keep in mind the NAM uses the GFS for boundary conditions so in some ways those two are on the same team and so we have the ECMWF vs the Met Office vs NCEP vs CMC. Essentially 4 different centers with their own unique modeling capabailities. Notice the ECMWF and GGEm are almost in the same location, the NAm is furthest North, the GFS and UKMET are in similar locations. The UKMEt looks to take a further south track than the GFS though if the 48-60 time frame though I havent seen the 54 hour map. Good post Allan... I would weight heavily on the UK/CMC/EC at this point given better continuity, and as you hinted at earlier, the op EC not likely an outlier within its own suite. Maybe a little more towards the CMC given its fairly consistent evolution with the system over the last 3-5 days. With that being said, we're probably looking at a 1002mb low splitting the difference between Montgomery and Birmingham Sunday morning. From the outputs you posted above the biggest difference I see in addition to the slp placement is the axis of the warm front, i.e. path of least resistance. UKMET/CMC/EC would argue for a track and exit somewhere near or just above CHS, maybe CHS-MYR. GFS/NAM looking like ILM. Link to comment Share on other sites More sharing options...
eyewall Posted February 17, 2012 Share Posted February 17, 2012 This afternoon's RAH disco is why I love that office as much as I do. We of course have to watch the phasing carefully and the amount of upper level support that will be available. I hope this storm is able to get itself together in the way the Euro wants it to for obvious reasons. With that said this will be exciting to watch. Hopefully this storm can deliver at least a little something for most who are riding the line. Link to comment Share on other sites More sharing options...
griteater Posted February 17, 2012 Share Posted February 17, 2012 I believe this is from the RPM model (not sure), from TV station out of Chattanooga....you can see it picking up on the damming in central / western NC by late Sunday morning. You can run the full regional loop here - http://www.wdef.com/...FutureCast.aspx Link to comment Share on other sites More sharing options...
WeatherNC Posted February 17, 2012 Share Posted February 17, 2012 This afternoon's RAH disco is why I love that office as much as I do. We of course have to watch the phasing carefully and the amount of upper level support that will be available. I hope this storm is able to get itself together in the way the Euro wants it to for obvious reasons. With that said this will be exciting to watch. Hopefully this storm can deliver at least a little something for most who are riding the line. ...SIGNIFICANT STORM SYSTEM TO IMPACT THE CAROLINAS THIS WEEKEND... OVERVIEW: A SOUTHERN STREAM UPPER LOW CURRENTLY OVER NORTHERN MEXICO WILL TRACK EAST TO WESTERN TX BY 12Z SAT. NORTHERN STREAM SHORTWAVE ENERGY CURRENTLY (18Z) OVER THE DAKOTAS IS EXPECTED TO TRACK SLOWLY SOUTH/SE INTO THE CENTRAL PLAINS BY 12Z SAT...WITH ADDITIONAL NORTHERN STREAM SHORTWAVE ENERGY (CURRENTLY IN MT/WY) ALSO DIGGING SOUTHEAST INTO THE CENTRAL PLAINS BY THAT TIME. ON SAT/SAT NIGHT... THE AFOREMENTIONED WAVES ARE EXPECTED TO INTERACT AS THEY PROGRESS THROUGH THE CENTRAL MS RIVER VALLEY INTO THE WESTERN TN VALLEY. THE RESULTING UPPER LEVEL WAVE (OR AMALGAMATION OF WAVES) IS PROGGED TO TRACK EAST OVER THE CAROLINAS/MID-ATLANTIC ON SUNDAY/SUNDAY NIGHT BEFORE MOVING OFFSHORE BY SUNRISE MONDAY MORNING. IN THE LOWER LEVELS...A LOW PRESSURE SYSTEM IS PROGGED TO DEVELOP ALONG THE TX GULF COAST SATURDAY MORNING...DEEPENING TO ~1000 MB AS IT TRACKS NORTHEAST INTO AL/GA BY 12Z SUN. FURTHER DEEPENING IS EXPECTED AS THE LOW TRACKS ENE ALONG THE CAROLINA COAST DURING THE DAY SUNDAY... FOLLOWED BY RAPID DEEPENING LATE SUNDAY NIGHT INTO MONDAY AS THE LOW PRESSURE SYSTEM TRACKS OFFSHORE INTO THE ATLANTIC. MODEL DISCUSSION/CONFIDENCE: MODEL GUIDANCE HAS BEEN IN GOOD AGREEMENT ON THE BROAD PATTERN WITH THE UPCOMING STORM SYSTEM...ALTHOUGH THE NAM/GFS/ECMWF ARE STILL HAVING A DIFFICULT TIME DETERMINING HOW MUCH PHASING WILL OCCUR BETWEEN THE AFOREMENTIONED NORTHERN/SOUTHERN STREAM SHORTWAVES AS THEY APPROACH AND CROSS THE CAROLINAS/MID-ATLANTIC SUNDAY AND SUNDAY NIGHT. GUIDANCE HAS TRENDED OVERALL TOWARD A SLIGHTLY COLDER SOLUTION...WITH A SURFACE LOW TRACK SOUTH OF CENTRAL NC AND THEN ALONG/OFFSHORE THE CAROLINA COAST. IN PARTICULAR...THE 12Z ECMWF NOW SHOWS MORE PHASING BETWEEN THE NORTHERN/SOUTHERN STREAM WAVES AS THEY APPROACH THE CAROLINAS...WITH A SURFACE LOW THAT IS DEEPER AND CLOSE TO THE NC COAST (991 MB 100 MILES EAST OF HATTERAS) THAN THE 12Z GFS/NAM (OR ANY PREVIOUS RUN OF ALL 3 MODELS). WITH THE ABOVE IN MIND...THE THREAT FOR SEVERE WEATHER HAS DECREASED (SUPPRESSED WELL SOUTH OF NC OR OFFSHORE)...AND THE THREAT FOR A PERIOD OF WINTRY WEATHER HAS INCREASED LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. PRECIPITATION CHANCES: LITTLE CHANGE WILL BE MADE TO THE PRECIP FORECAST FOR SATURDAY THROUGH SUNDAY AFTERNOON. EXPECT INCREASING CHANCES FOR RAIN FROM SW-NE BY OR SHORTLY AFTER SUNSET SATURDAY EVENING...OVERSPREADING THE ENTIRE AREA BY OR SHORTLY AFTER MIDNIGHT AND PERSISTING THROUGH SUNDAY MORNING. THE 12Z GUIDANCE SHOWS A PRONOUNCED DRY SLOT PUNCHING INTO THE AREA IN ADVANCE OF THE APPROACHING UPPER LEVEL WAVE BY ~18Z...AND THIS MAY HELP SUPPRESS MEASURABLE PRECIP FOR A PERIOD OF TIME SUN AFTERNOON (BECOMING DRIZZLE/PATCHY LIGHT RAIN). BY LATE SUN AFTERNOON/EVENING...MID/UPPER LEVEL ASCENT ASSOCIATED WITH THE APPROACHING SHORTWAVE WILL HELP RE-SATURATE THE MID-LEVELS OVER AT LEAST THE NORTHERN HALF OF CENTRAL NC (NORTH OF HWY 64)... AND CHANCES FOR MEASURABLE PRECIP SHOULD INCREASE AGAIN BETWEEN 21Z SUNDAY AND 06Z MONDAY MORNING...PRIMARILY NORTH OF HWY 64. PRECIP CHANCES WILL DECREASE AND END FROM WEST-EAST BY OR SHORTLY AFTER 06Z AS THE UPPER LEVEL WAVE AND ASSOCIATED SFC LOW PROGRESS EAST/ OFFSHORE. GIVEN THE DYNAMICS IN PLACE...RAIN IS EXPECTED TO BE MODERATE TO HEAVY AT TIMES SATURDAY NIGHT THROUGH LATE SUNDAY MORNING. A WIDESPREAD INCH OF RAINFALL APPEARS LIKELY OVER THE AREA...WITH LOCALLY HIGHER AMOUNTS POSSIBLE. WINTER WEATHER THREAT: AS MENTIONED ABOVE...CONFIDENCE HAS INCREASED THAT A PERIOD OF WINTRY WEATHER WILL OCCUR OVER PORTIONS OF THE AREA LATE SUNDAY INTO SUNDAY NIGHT. DUE TO THE COMPLICATED NATURE OF THE UPPER LEVEL PATTERN AND THAT A SLIGHT CHANGE IN THE EVOLUTION OF THE APPROACHING UPPER LEVEL WAVE AND SUBSEQUENT LOCATION/STRENGTH OF THE SURFACE LOW COULD HAVE SIGNIFICANT IMPLICATIONS FOR THE PTYPE FORECAST IN CENTRAL NC...IT REMAINS DIFFICULT TO PIN DOWN THE LOCATION/TIMING OF ANY PTYPE CHANGES AND POTENTIAL ACCUMULATIONS. HOWEVER...THE 12Z GFS/NAM/ECMWF ALL SHOW MEASURABLE PRECIP IN ASSOC/W THE UPPER LEVEL WAVE SUNDAY EVE/NIGHT (ESPECIALLY NORTH OF HIGHWAY 64) AT THE SAME TIME AS THE SURFACE LOW TRACKS OFFSHORE AND STRONG NORTHERLY COLD ADVECTION RAPIDLY ADVECTS A COLDER AIRMASS SOUTHWARD INTO CENTRAL NC. BASED ON THE 12Z GFS/NAM AND 00Z ECMWF...A CHANGEOVER FROM RAIN TO SNOW WOULD OCCUR NORTH OF HWY 64 BETWEEN 00-06Z MONDAY...WITH A POTENTIAL FOR LIGHT ACCUMULATIONS (DUSTING TO 1") NORTH OF THE I-40/85 CORRIDOR TOWARD THE VA BORDER...WHILE SOUTH OF HWY 64 MID/UPPER LEVEL ASCENT ASSOC/W THE APPROACHING SHORTWAVE WILL BE LESS LIKELY TO SATURATE THE ICE NUCLEATION ZONE AND A CHANGEOVER FROM LIGHT RAIN/DRIZZLE TO FZDZ/FZRA WOULD BE MORE LIKELY (ASSUMING STRONG COLD ADVECTION/WETBULBING ALLOWS TEMPS TO FALL BELOW FREEZING PRIOR TO PRECIP ENDING). THE LATEST 12Z ECMWF SOLUTION IS A BIT MORE OMINOUS...SHOWING A POTENTIAL FOR A FEW INCHES OF SNOW ACCUMULATION ALL THE WAY SOUTH TO HIGHWAY 64...INCLUDING THE TRIANGLE. BOTTOM LINE...ALTHOUGH THE SPECIFICS REMAIN DIFFICULT TO PIN DOWN...A PERIOD OF WINTRY WEATHER IS BECOMING INCREASINGLY LIKELY ACROSS CENTRAL NC LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. THE MAJORITY OF MODEL GUIDANCE (ASIDE FROM THE 12Z ECMWF) INDICATES THE WINTER WEATHER THREAT WOULD OF THE NUISANCE VARIETY...AND CONFINED PRIMARILY TO AREAS NORTH OF HWY 64. HAVING SAID THAT...IT WILL BE INTERESTING TO SEE IF SUBSEQUENT MODEL RUNS TREND TOWARD THE 12Z ECMWF...OR IF THE 12Z ECMWF IS JUST AN ANOMALY. -VINCENT Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 17, 2012 Share Posted February 17, 2012 Sometimes I wish NWS Raleigh would cover my county instead of Blacksburg...they are much more optimistic outside of the mountains in their discussions. Blacksburg is conservative but still accurate. Raleigh: Bottom line...although the specifics remain difficult to pin down...a period of wintry weather is becoming increasingly likely across central NC late Sunday afternoon into Sunday night. The majority of model guidance (aside from the 12z ecmwf) indicates the winter weather threat would of the nuisance variety...and confined primarily to areas north of Highway 64. Having said that...it will be interesting to see if subsequent model runs trend toward the 12z European model (ecmwf)...or if the 12z European model (ecmwf) is just an anomaly. -Vincent Link to comment Share on other sites More sharing options...
Brick Tamland Posted February 17, 2012 Share Posted February 17, 2012 Yes, the fun part is going to see if the Euro is right and on its own, or if all the other models will trend toward the Euro. Link to comment Share on other sites More sharing options...
Solak Posted February 17, 2012 Share Posted February 17, 2012 From the RAH Facebook page... http://www.facebook....ice.Raleigh.gov Link to comment Share on other sites More sharing options...
packbacker Posted February 17, 2012 Share Posted February 17, 2012 Well the 18z GFS shifted south a little when compared to the 12z, really close to the Euro, but the precip shield didn't shift that much, so the question is who is handling that better, the Euro or GFS. It seems to me the NAM is not even close to either model, and can be thrown out. Link to comment Share on other sites More sharing options...
burgertime Posted February 17, 2012 Share Posted February 17, 2012 Well the 18z GFS shifted south a little when compared to the 12z, really close to the Euro, but the precip shield didn't shift that much, so the question is who is handling that better, the Euro or GFS. It seems to me the NAM is not even close to either model, and can be thrown out. 18z does the old 6-10 split between the mountains and just east of RDU with the heavy precip. Link to comment Share on other sites More sharing options...
superjames1992 Posted February 17, 2012 Share Posted February 17, 2012 So says the person sitting pretty in Raleigh Actually, I'll be in High Point this weekend (at home), so I'm in a better position! Things aren't looking good in CLT, to be sure, but they never were looking good in the first place. I'm going to try to stay in GSO for this one if I can, but I need to get back to Raleigh by Monday morning for classes, so we'll see. I'm desperate to see some snow before winter's conclusion, though... Link to comment Share on other sites More sharing options...
phil882 Posted February 17, 2012 Share Posted February 17, 2012 What did I say about not giving up guys . I'll have a much more detailed post later tonight for my friends in the southeast. I'll give you a bit of a teaser though... the WNC have a good shot and picking up a great deal of snow thanks in large part to adiabatic lifting over a damming profile. Stay tuned Link to comment Share on other sites More sharing options...
WilkesboroDude Posted February 17, 2012 Share Posted February 17, 2012 18Z RGEM Snowfall Link to comment Share on other sites More sharing options...
FSUIZZY Posted February 17, 2012 Share Posted February 17, 2012 Actually, I'll be in High Point this weekend (at home), so I'm in a better position! Things aren't looking good in CLT, to be sure, but they never were looking good in the first place. I'm going to try to stay in GSO for this one if I can, but I need to get back to Raleigh by Monday morning for classes, so we'll see. I'm desperate to see some snow before winter's conclusion, though... I may just drive to see snow. It may be my only chance. Make a nice day of it, take the lady out. "We're going out for a picnic!" She'll think I'm a romantic, I'm just doing it for the snow. Link to comment Share on other sites More sharing options...
tnweathernut Posted February 17, 2012 Share Posted February 17, 2012 What did I say about not giving up guys :-). I'll have a much more detailed post later tonight for my friends in the southeast. I'll give you a bit of a teaser though... the WNC have a good shot and picking up a great deal of snow thanks in large part to adiabatic lifting over a damming profile. Stay tuned Doesn't sound like a scenerio that will help northeast TN, but it's nice to see you dropping in on the southeast forum. It will be fun to watch events unfold later this weekend. Look forward to your discussion. Link to comment Share on other sites More sharing options...
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